A regulated power supply is an electronic component that supplies electrical energy to an electrical load. Normally, most power supplies regulate either their output voltage or output current to remain at a preset, constant level, despite variations in the load.
In the case of a typical audio amplification system, an audio amplifier uses the electrical energy from a voltage regulated DC power supply to amplify an audio signal to drive a loudspeaker driver, where the amplifier and the driver are together acting as the load. If, however, the electrical power required by the audio amplifier to amplify the audio signal exceeds the power available from the power supply, performance by the loudspeaker driver may suffer. For example, when the amplifier attempts to overdraw the power supply during a peak excursion of an audio signal, such as a large bass hit, the regulated DC voltage drops thereby causing loudspeaker performance to suffer. A local energy storage device such as a capacitor may be added to the output of the power supply, to assist with meeting such peak power demands.